Technical Field
The present disclosure relates to a power converter. More particularly, the present disclosure relates to a power converter capable of protecting against a short circuit.
Description of Related Art
In the applications of high-power converters, such as high-voltage converters, solar inverters, semiconductor switch is usually utilized to adjust the voltage and frequency of power converters. If the power converter operates in an abnormal condition, such as a short circuit, the semiconductor switch is usually affected. As a result, the operations of the power converter are failed.
One of common semiconductor switch is insulated gate bipolar transistor (IGBT). FIG. 1A depicts a schematic diagram of an IGBT 100. FIG. 1B depicts a schematic diagram of a waveform of the IGBT in FIG. 1A when it works in short circuit condition.
As shown in FIG. 1A, IGBT 100 has a gate (G), a collector (C), and an emitter (E).
As shown in FIG. 1B, one situation is that the circuit where IGBT 100 of a power converter works in pre-short circuit condition (that is, waveform 101). Another situation is that the circuit works in short circuit condition (that is, waveform 102) when IGBT 100 is turned on. As shown in FIG. 1B, when a short circuit occurs, the current IIGBT of IGBT 100 is substantially increased and the voltage VCE between the collector (C) and the emitter (E) also rises. At this time, the IGBT 100 is required to sustain a higher power, it will possibly shorten the lifetime or degrade the performance of IGBT 100. As a result, the reliability of the power converter is reduced.
For the forgoing reasons, there is a need for solving the above problems of short circuit protection in power converter using semiconductor switch, which is one of the important research subjects and an objective that the industry endeavor to improve.